Technical Abstract:
Beans are the most important grain legumes for direct human consumption in the world, particularly for poor people in Latin America and Africa, and for this reason are the model food-legume of choice (Broughton et al., 2003). Rapid improvement of their agronomic and nutritional characteristics is dependent on developing a genetic platform that includes mutagenesis and screening protocols that will permit plant scientists all over the world to conduct both forward and reverse genetics. Thus an ethyl methane sulphonate (EMS)-induced mutant collection of common beans (Phaseolus vulgaris cv BAT93) is being created at the University of Geneva, the USDA-ARS in Puerto Rico, and at CIAT in Cali, Colombia. This collection now comprises about 1,500 M2 as well as about 900 M3 lines and is being used to isolate mutants deficient in nodulation, and seed development. Of the 348 M2 lines tested, 58 plants with altered nodulation patterns have been identified. In another screen, seeds of two plants (out of 62 tested) failed to develop normally while seeds of another two mutants aborted within 15 to 25 days after anthesis. Other aspects of this programme include: (a) using proteomics approaches to establish a baseline for protein analysis; (b) to identify seed size mutants; (c) to use forward and reverse genetics for the analysis of seed color mutants and thus elucidate major parts of the flavonoid to condensed tannin pathway. TILLING (Targeted Induced Local Lesions IN Genomes) protocols are being developed to isolate these lesions, and large-scale random-sequencing of the P. vulgaris genome has been initiated. Seeds of the EMS collection will be freely made available to researchers for phenotypic screening of traits of interest.